The present invention relates to a simultaneous executable multiplicity adjustment system and method for determining a simultaneous executable multiplicity as an upper limit value corresponding to a maximum number of requests simultaneously executable in a distributed system (in particular, Web system) having a plurality of divided sub-systems.
A distributed system (in particular, Web system) having a plurality of functionally-divided sub-systems has a complicated structure because the system has many elements. Even when a system looks like a virtually single system when viewed from system users, the structure of a server is divided into elements according to a logical or physical boundary such as business type, development department, sub-network or the like. By combining such elements called sub-systems, a total system can be realized.
For this reason, the cause of a problem such as performance bottleneck is also complicated, and thus it is difficult to suitably design a multiplicity, considering also the influences on other systems cooperated therewith. Meanwhile, it is desirable to stably run the system and establish optimum system environments satisfying performance requirements. In other words, it is desirable to set the system considering an optimum trade-off between the performance bottleneck and the system stability.
JP-A-5-173807 discloses a technique in which, for solving a performance bottleneck, the number of simultaneously-executable jobs (job executable multiplicity) is set from a job input queue, and the job executable multiplicity is changed according to a measured server load quantity. JP-A-5-143559 discloses a technique in which, of service computers which informed of their load states in response to a load state notification, the service computer having a lightest load is found to be connected.